Electron discharge device



Dec. 8, 1931. F. 1.. HUNTER, JR., ET AL 1,835,051

ELECTRON DI SCHARGE DEVI C E Filed Dec. 15, 1923 V and supports shownPatented Dec. 8, 1931 UNITED STATES PATENT OFFICE FREDERICK L. HUNTER,JRt, OF TOWACO, AND SYLVESTER W. CROWLEY, OF WEEHAW- KEN, NEW JERSEY,ASSIGNORSTO DE FOREST RADIO TELEPHONE &; TELEGRAPH (30., OF JERSEY CITY,NEV JERSEY, A CORPORATION OF DELAWARE ELECTRON DISCHARGE DEVICEapplication filed. December 15, 1923. Serial No. 680,850.

This invention relates to electron discharge devices, and particularlyto such devices as are used in connection with telephonic andtelegraphic apparatus; 7

Heretofore considerable difiiculty has been encountered with microphonicdisturbances in connection with electron discharge devices. It has beennoticed thatv these disturbances have occurred when the electrondischarge deviceis in any way mechanically jarred,

which obviously may happen in a great va-.

riety of ways such as by knocking the device, manipulating the apparatuswith which it is mechanically connected, by vibrations of the support oreven the building caused by a passing vehicle, and so forth. I

The objects of the present invention'are to overcome the microphonicdisturbances in an electron discharge device; to provide a-structure ofan electron discharge device substantially incapable of microphonicdisturbances created by exterior mechanical movement; to thus increasethe efficiency and utility of the electron discharge device; to providea structure wherein the operative elements are prevented from separatelyvibrating or oscillating; to minimize the longitudinal distance of theoperative elements from the stem or support; to overcome breaking of thefilament by distortion; to secure simplicity of construction,manufacture, assemblyand economy of materials, and to obtain otheradvantages and results as may be brought out in the followingdescription.

Referring to the accompanying drawings in which like numerals ofreference indicate similar parts throughout, Figure 1 is a perspectiveview of an electron discharge device constructed in accordance with thepreferred embodiment of our invention. Fig. 2 is a side View showing therelation between the electrodes, the press, and the electrode supports.Fig. 3 is a top plan view of the press in Fig. 2.

In said specific embodiment of the invention disclosed in said drawings,the reference numeral 1 indicates the glass casing or bulb as nowemployed in electron discharge devices which is provided with a suitablebase 2 of metal or other suitable material, and which may be evacuatedas heretofore common in the art. Within said casing or bulb l isprovided the usual stem or support 3 through which the variousconnections are made from exterior prongs 4 to the operative elements 5within said casing or bulb.

The operative elements in the present dis closure include a tubularplate 6 constituting the anode, which is disposed transversely withrespect to the stem or support 3 and preferably as close thereto as ispractical in the manufacture of the same. It is to be observed that themounting of said plate in the structure shown is by means of two wires7, 7 extending into the end of the stem, one of the wires, as 7,continuing downwardly through the stem for electrically connecting withone of the prongs 4. I

Extending longitudinally through the cylindrically formed plate, is afilament or cathode 8 which is preferably centrally disposed withrespect to said plate, and proportioned so as to project beyond the endsof the plate. The projecting ends of said filament or cathode 8 areattached to or carried by wires 9, 10 which are bent to pass alongtheoutside of the plate to the stem or support and then downwardly intosaid support, connecting at their lower ends to two of the prongs 4 soas to admit a flow of current to the filament. It is to be noted that bythe structure disclosed and particularly by placing the plate close tothe stem or supportl3, the wires 9, 10 have practically no length beyondthe stem in a direction longitudinally thereof. In other words, theexposed or sup} porting portionof said wires is reduced to a minimum andparticularly reduced to a minimum for parallel portions thereof.

' Surrounding the filament in the particular construction shown in thedrawings, is a grid 11 in the shape of a coildisposed within the anodeor plate 4. Said grid or coil 11 is mounted at its opposite ends at theends of the plate, to suitable supporting wires 12,v 13, which, like thesupporting wires for the filament, are appropriately bent to pass along.the outside of the plate to the stem or support 3 andthen downwardlyinto said stem. One of said wires, as 12, continues downwardly throughthe stem to make connection with the fourth of the prongs 4:. Hereagain, attention is to be called to the fact that these supporting wiresalso have practically no length beyond the stem in a directionlongitudinally thereof so'that the exposed or supporting portion of saidwires is reduced to a.

minimum and particularly reduced to a mini mum foriparallel' IJ'OI'tlOHSthereof.

,. .We Wish to mention;- at this point-{that the usual filament employedin an electron dis charge device is generally brittle, and whilesufficiently strong to Withstand tensile stra ns, will not withstandshearing stresses. It otten happens that vibrations or otherdisturbances or causes will result in the opposite supportedends' notbeing in direct alinement and as a result break the filament. The abovedescribed structure eliminates a large portion of the causes forbreaking the filament, but

in order to secure a'support whichis-less likely toresult in breakage,we preferably provide a resilient support for the filament.

In the drawingswe have shown a leaf spring 14' eXtending transverselyfrom the filament 8ft'o the supporting wire 9,.an'd welded, sol- Ideredorlotherwise affixed to a portion of each.

While other forms of springs may be used,

I the one described and shown has proven satisfacto'ry, it being of suchastructure as to not microphonic and yet adapted to both flex and a'cconnnodatetorsion. I I I The structure thus described providessupports/for the operative elements,that for the plate, filament andgrid, which cannotindependently vibrate or act in the nature of a tuningfork under mechanical impulse derived from exterior sources. e wish toadd,

howeveij thatwhilewe have shown the operat'ive elements disposedtransversely with respect to thestem, it iswithin the scope ortheinvention to provide other disposition thereof so long as the saidelements have a common support tov whichthey are attached with minimuminterveningsupports'. -And ifurt'hermore,we may add that while we haveshown and mentioned a stem as the supporting means for the-operativeelements, we

- -Having thus do wish it understood in connection withv bothdescription andcla'ims that we include; in the diameter of .said anode.

ing from said stem, a substantially cylindrical plate arrangedtransversely with respect I to said stem and having mounting means onsaid plate for receiving wires from the stem substantially'tangent tothe plate, said mounting means having a length less than the diameter ofthe plate whereby the plate may be mounted in close associationto thesaid stem.

2;An electron 'discharge device having a stem with a press'portion, aplurality of support and lead-in wires sealed into said press, certainof said supports being stublike, a cylindrical plate tangentiallysupported at its" central portion from said stublike supports and havingits axis substantially parallel with the edge of said pressand at adistance therefrom less than the diameter of's'aidplate.

I 3. An electron discharge device having a ress ortion an electronemittin cathode supported from said press with all the .points thereofin close proximity. to said press, an anode surrounding said cathode,and stub supports having their ends connected to said stem and the otherends rigidly attached tangentially to said anode atits central portiononlyto prevent relative movement between said anode and said press, saidanode being supported on said supports from the edge of said press adistanceless than the 4. electron discharge device having a pressportion, an electron emitting cathode supported from said, press andarranged substantially,parallel to the 'edge of said press and in: closeproximity thereto,1a control grid surrounding said cathode, and an anodesurrounding said control grid, a plurality of support and lead inwiresattached tosaid stem, certain of said wires being stublike and havingone end thereof rigidly unitedtangentially to said anode, said wiressupporting said anode at a distance from the edge of said press lessthan the diam eterof said anode. I II I I FREDERICK-L.'HUNTER, JR.ISYLVESTER CROWLEY.

term any support whether it is ,or is not the conventional stem now.known to the art.

Qbviously othermodilications and changes I i v Y may be made in-themanufacture and use of our improvedelectron discharge device with- 1 I Iout departing from the spirit'or scope, ofthe invention, and wedojnotwishto be'understood as restricting ourselves to the exact structureshown or described except. asset forth infthe followingclaims whenconstrued inthe light of the prior art. f ribed' our invention, we

claim:

1L; An felectrondischarge device comprise I .inga stem,';lead andsupporting wires issurod

